Method for cutting continuous yarns

ABSTRACT

A method for cutting continuous yarn includes compacting the yarn into a tubular piling in which the yarn is randomly curled. The piling is then sliced continuously as it is being formed to obtain a plurality of individual strands. The piling may be cut completely therethrough to form the strands or, on the other hand, may be cut only partially therethrough to form the strands. In either case, since the yarn has been curled randomly before being cut, the distribution of strand length obtained by cutting the piling will be variable.

United States Patent Sangalli et a1.

METHOD FOR CUTTING CONTINUOUS YARNS Inventors: Silvio Sangalli, Caluire; Roger Vidal,

Champagne, both of France Rhone-Poulenc-Textile, Paris, France Filed: Jan. 28, 1974 Appl. No.: 436,911

Assignee:

Foreign Application Priority Data Feb. 8, 1973 France 73.05069 U.S. Cl 57/157 R; 28/7214; 57/2; 83/913 Int. Cl. D0lg 1/O4;D01g l/l0 Field of Search 57/1 R, 2, 34 R, 34 HS, 57/156, 157 R; 28/7214; 83/913; 19/0.6

References Cited UNITED STATES PATENTS Speakman 83/913 X [451 Aug. 26, 1975 3,050,928 8/1962 Sumncr 57/2 3,241,195 3/1966 Bacr 83/913 X 3,373,470 3/1968 Joly 57/34 HS 3,530,751 9/1970 Munroe 83/913 X 3,606,655 9/1971 Oberlandcr et a1 28/7214 UX 3,751,778 8/1973 Grosjean 28/7214 Primary Examiner-Donald E. Watkins Attorney, Agent, or Firm-Sherman & Shalloway 57 ABSTRACT A method for cutting continuous yarn includes compacting the yarninto a tubular piling in which the yarn is randomly curled. The piling is then sliced continuously as it is being formed to obtain a plurality of individual strands. The piling may be cut completely therethrough to form the strands or, on the other hand, may be cut only partially therethrough to form the strands. In either case, since the yarn has been curled randomly before being cut, the distribution of strand length obtained by cutting the piling will be variable.

14 Claims, 3 Drawing Figures PATENTED AUG 2 51975 FIGZ BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to methods of cutting textile material and the products obtained thereby, and more particularly this invention relates to methods of cutting textile material and the products obtained thereby wherein continuous filaments are severed to form multiplicities of individual filaments.

2. Prior Art and Technical Considerations In the manufacture of textile fabrics or articles from artificial or synthetic materials, continuous multistrand yarns are utilized, it is also possible to use spun yarns made from staple fibers. These fibers are obtained by breaking or cutting continuous yarns at predetermined lengths. This is usually accomplished by utilizing blades which are affixed to the periphery of rotating discs. The continuous yarns may be out either while in single strand form or curled form. The methods and apparatus utilized by the prior art for cutting yarns into fibers have two major deficiencies in that the supply of yarn being cut generally cannot advance at speeds exceeding 300 meters per minute and the strands tend to stick together after cutting due to heat generated in the strands as they are cut. This latter problem is known as out fusion.

In order to overcome these deficiencies, the U.S. Pat. No. 3,530,751 discloses a method in which continuous yarn is formed into a rope which is folded upon itself to form a zig-zag piling with parallel folds in which filaments are disposed parallel to one another. When this rope is cut, the fibers obtained have a regular length if the cut is performed periodically but may have various lengths if the cut is performed by varying the number of cutting elements for the lateral position of a single cutting element. When fibers of various lengths are produced, the fibers of identical lengths are packaged together. Accordingly, the distribution of the lengths of the fiber is step-like. This step-like distribution presents problems when the fibers are utilized in the worsted and woolen spinning system. In these spinning system,.

fibers having a variable length of 35 mm to 350 mm are used. In order to produce yarns which have a staple fiber distribution similar to that of wool, the fibers utilized must have a distribution similar to that of wool fibersSuch a distribution is not obtainable by utilizing the disclosure of U.S. Pat. No. 3,530,751. I

Another approach suggested by the prior art is to cut continuous strands of yarn by utilizing lasers. The yarn utilized in this approach is formed into curled/noncurled ropes which are then rectilinearly presented to the laser beams for cutting. This approach has the same general deficiencies as U.S. Pat. No. 3,530,751.

SUMMARY OF THE INVENTION In view of the aforementioned deficiencies of the prior art approaches, it is an object of the instant invention to provide a new and improved method of cutting yarn to form staple fibers wherein the yarn is cut while being fed at high speed to a cutting apparatus.

It is another object of the instant invention to provide new and improved methods for cutting yarn wherein cut fusion is avoided so that the fibers produced by the cutting method do not adhere together.

It is still another object of the instant invention to provide new and improved methods of cutting continuous yarn to form individual fibers wherein the lengths of the fibers obtained by the cutting method are distrib uted in a random fashion resembling the distribution of sheared wool fibers.

It is still another object of the instant invention to provide new and improved methods of cutting yarn supplied in the form of a continuous strand at speeds greater than 300 meters per minute and approaching 3000 meters per minute.

It is still a further object of the instant invention to provide a new and improved method for cutting yarn continuously as it is produced so as to provide an integrated line for yarn fabrication.

It is an additional object of the instant invention to provide new and improved methods for cutting yarn wherein the actual cut is performed at a relatively slow speed of product advance while the product is being produced at a relatively high speed.

It is still another object of the instant invention to provide fibers produced in accordance with the aforedescribed methods.

A method for practicing the instant invention includes compacting a strand of multifilament yarn into an elongated piling wherein the yarn is distributed in the form of random curls and then cutting the piling to form a plurality of fibers. The instant invention also contemplates either cutting the piling completely therethrough to form the individual fibers or partially therethrough to form the individual fibers. In order to cut the multifilament yarn in a continuous process as it is formed, the yarn is entrained in a stream of fluid which injects the yarn into a tube where the piling is formed and from which the piling continuously emerges. The instant invention also contemplates the individual fibers obtained by cutting the piling.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of an apparatus for practicing a method according to the instant invention wherein a piling of yarn is generated in a tube and is sliced by a blade as it emerges from the tube;

FIG. 2 is a side view partially in section showing a second embodiment of apparatus for practicing a method of the instant invention wherein a rotating cutting blade is positioned within the tube which forms the pilings; and

FIG. 3 is a third embodiment of apparatus for performing the method according to the instant invention wherein a rotating cutting blade is positioned downstream from the tube which forms the piling.

DETAILED DESCRIPTION Referring now.to FIG. 1, there is shown a cylindrical piling, designated generally by the numeral 10, which is composed of either a single strand or a plurality of strands of multiflament yarn 11. The piling 10 is formed in a tube 12 as the strand or strands 1 l are fed into the tube 12 by an entraining stream of air that surrounds the strand or strands 11 in an ejector nozzle 14 located at the downstream end 15 of the tube 12. As

the fluid stream expands in the tube 12, it exits through lateral openings 16 formed in the periphery of the tube. The strand 11 is advanced to the nozzle 14 as it is produced by a spinning, extrusion or other process schematically illustrated as the box 18.

The term piling is meant to define a process in which a strand of yarn is compacted in a curved flexible form. In the instant invention, the piling is made of lay ers of yarn which are individually curved in a random manner and which are not adhered or otherwise attached together. The curled yarn forms convolutions which are not necessarily folded in the same plane nor are necessarily parallel or in zig-zag relationship to one another.

The fluid which is used to entrain and inject the yarn 11 into the tube 12 may be inert with relation to the yarn and perform no process or operation thereon or may include substances such as dyes or other chemicals which will react in some way with the yarn 11. Devices for forming such pilings are illustrated in US. Pat. Nos. 3,373,470; 3644969; 3703754; 3751778.

The piling 10 can be made of either one or several artificial yarns 11. The yarns 11 may be twisted or not twisted or may either be dyed or not dyed. The yarns 1 1, when a plurality of yarns are used, may all be identical or they may be different and the diameter of the piling 10 may be any convenient dimension. Generally, the yarn utilized in practicing the method of the instant invention may therefore be of any convenient nature or configuration.

As seen in FIG. 1, as the piling l emerges from a downstream end 20 of the tube 12, it is cut by a stationary blade 21 which is positioned between a pair of rollers 22 and 23 which align the piling 10 with the blade 21. The blade 21 may either cut completely through the piling 10, as shown in FIG. 1, or may cut partially through the piling 10. As the blade 21 cuts the piling 10, the strand or strands 11 are separated into a plurality of individual fibers. Since the strand 11 is randomly curled within the piling 10, the individual fibers will be of unequal lengths. Variations in the depth of cut may be achieved by mounting the blade 21 in a slide 25 which permits the blade to move normally with respect to the longitudinal axis of the piling 10.

In order to produce fibers which will have a distribution similar to that of sheared wool, the blade 21 is positioned so as to cut completely through the piling 10. In this case, the fibers will have a length between 35- 350 mm which is a distribution similar to that of wool and which, when processed in the same manner as wool, will produce textile materials having threads of a wool-like configuration.

The blade 21 thus cuts the piling 10 as the yarn 11 is produced. Since the tube 12 in effect distributes the yarn in three dimensions instead of two, yarn arriving at the nozzle 14 with a velocity of 300 3000 meters per minute is slowed in its direction of advance to a speed of 150 meters per minute. This reduced speed enables the blade 21 to cut the yarn 1 l at a slower velocity but higher density, which facilitates cutting the yarn. Since the yarn 11 is layered within the piling in a progression of convoluted curls, the yarn will not fly off in all directions as it is severed but will, rather, hold its configuration until after it passes between the rollers 22 and 23 and over the blade 21.

If the piling 10 is out completely therethrough, the resulting fibers can be collected in a container (not shown) or pneumatically transported by suitable means (not shown) to a storage bin (not shown) or the like. If desired, the fibers can be transported to a press (not shown) or perhaps to an opener (not shown) which separates the fibers by opening the two halves 10a and 10b of the piling. If the two halves, 10a and 10b, are opened to separate the fibers, the fibers may then be fed to an assembly for making layers (not shown) or else to a device (not shown) for making fiber threads. If the piling 10 is only partially cut, the piling can be collected into a bin (not shown) or be wound upon a spindle (not shown).

Referring now to FIGS. 2 and 3, instead of using a stationary blade such as the blade 21 of FIG. 1, it is possible to use a rotating blade such as the blade 31 of FIGS. 2 and 3. The rotating blade has the advantage of continuously passing through more than one station. Consequently, the blade 31 may be sharpened by a sharpener schematically shown by the numeral 33 as it I severs or cuts the piling 10. This obviates the disadvantage of having to remove the blade periodically for sharpening as must be done with the blade 21 of FIG. 1. In FIGS. 2 and 3, the rotating blade 31 is shown positioned within a slot 34 in the tube 12 and downstream of the rollers, respectively. This is done to illustrate the flexibility and numerous approaches which may be utilized in practicing the method of the instant invention. It should be noted that in FIG. 2 the piling 10 is kept compacted by the tube 12 as it is severed by the rotating cutter 31 whereas in FIG. 3 the bias of the piling 10, due to the elasticity thereof, urges it between the cutter 31 and lower roller 23.

In keeping with the disclosure of embodiments incorporating the principles of the present inventions, it should be kept in mind that many additional variations are within the spirit of the instant invention. For example, the cutting means 31- and 21 may be placed intermittently in contact with the piling by withdrawing and advancing the cutters as the piling is advanced. In addition, the profiles of the cutters may be varied to advance or retard the cutting with respect to the depth at which the cutters slice. Although the illustrated embodiment utilizes rollers 22 and 23, it is also possible to use a pair of conveyor belts in order to advance the pi]- ing 10. In addition, while only one cutter 21 or 31 is shown in the figure, it is possible to use a plurality of cutters disposed in any configuration around the priphv have appeared in which a layer or strip of fiber is transformed directly into thread. These processes are gener-v ally referred to as open-end spinning and utilize mechanical, hydraulic, electrostatic and pneumatic machinery. Consequently, it is advantageous, when making thread from the fibers produced by the method of the instant invention, to utilize open-end spinning devices subsequent to the cutting operation herein des'cribed.

When a partial cutting is used, where the blades 21 or 31 do not cut completely through the piling 10, the resulting fibers are either twisted immediately in a continuous process or are collected and twisted later to form threads. The resulting thread contains fibers which are cut and uncut. This gives the thread a greater breaking resistance than that of other types of fiber threads in which all of the fibers are cut. It is possible to draw the fibers of the piling when the piling is partially cut to obtain, upon twisting the fibers, a yarn with a relatively high count from fibers having relatively fine counts.

By programming the depth of the cut into the piling 10, fancy or unusual threads may be obtained. These threads formed of fiber can be used for making fabric, knits or may be utilized in the manufacture of 'unwoven products or any other textile application.

EXAMPLES The following examples illustrate the principles incorporated in the invention but do not limit the invention.

EXAMPLE 1 Polyhexamethylene adipamide yarn having a count of 2300 dtx/ 136 strands of tetralobed section is produced by a spinning and drawing device and fed continuously at 1100 meters per minute to a pneumtic texturizing unit as described in US. Pat. No. 3751778. The diameter of the tube into which the yarn is fed is 10 mm which produces a piling having a diameter of 10 mm. Upon emerging from the tube, the piling passes between two rollers having a peripheral speed of 12.5 meters per minute and then engages a rotary blade similar to that shown in FIG. 3 which rotates 25 rpm. The blade penetrates the piling to a depth of 4 mm and cuts the piling into fibers having lengths in the range of 60 to 100 mm.

EXAMPLE 2 Viscose yarn having a count of 330 dtx/120 strands is fed from a spool at a rate of 400 meters per minute to a pneumatic texturizing device similar to that of US. Patent 3,703,756. The diameter of the tube in the texturizing device and the resulting piling is 4 mm. While in the tube, the piling is engaged by a rotating blade which penetrates 2 mm into the piling as it rotates at 25 rpm. The piling then passes between a pair of rollers having a peripheral speed of 9.8 meters per minute and the fibers obtained after opening the piling have a length in the range of 20 30 mm.

EXAMPLE 3 Two ethylene glycol polyterephthalate yarns having a count of 167 dtx/30 strands which are untwisted are fed at a rate of 800 meters per minute to a device as described U.S. Pat. No. 3703754 to produce a piling having a diameter of 4 mm. The resulting piling passes between two rollers having a peripheral speed of 18.9 meters per minute and is then cut as follows:

a. cut with a penetration depth of 1.5 mm via a stationary blade or disc turning at 25 rpm to produce fibers 50 60 mm in length;

b. cut with a penetration depth of 2.5 mm utilizing a stationary blade or cutting disc turning at 25 rpm to produce fibers having a length of mm.

EXAMPLE 4 Polyhexamethylene adipamide yarn having a count of 2300 dtx/ 136 strands of tetralobed section produced by a spinning-drawing device is fed at a rate of 1100 meters per minute to a pneumatic texturizing unit such as that described in US. Pat. No. 3,751,778 to produce a piling having a diameter of 10 mm. The resulting piling passes between two rollers having a peripheral speed of 12.5 meters per minute and then comes into engagement with a stationary blade placed parallel to its axis which penetrates the piling to a depth of 2 mm. The partially cut piling is then wound on a spool at a speed of 930 meters per minute and twisted at a rate of 40 turns per meter to obtain a thread-type product utilized in the fabrication of fabrics.

The aforedescribed drawings, illustrations and examples are merely descriptive of embodiments that the present invention may assume. The invention, however, is to be limited only by the following appended claims.

What is claimed is:

1. A method of cutting continuous multifilament yarns comprising the steps of:

compacting at least one strand of multifilament yarn into a flexible piling in which the strand is curled in a random fashion, and

cutting the strand after the strand has been compacted into the piling to form a plurality of separate strands of different lengths for use in further processing.

2. The method of claim 1 wherein the strand is compacted by injecting the strand into an elongated tube with an expanding fluid.

3. The method according to claim 1 wherein the piling is cut completely therethrough during the cutting step to obtain staple fibers of a variable length having a length distribution similar to that of wool.

4. The method according to claim 1 wherein the piling is not out completely therethrough during the cutting step to obtain a partially cut piling having individual strands of various lenghts.

5. The method of claim 4 further including the steps of twisting the individual strands of the partially cut piling to make thread. A

6. The method of claim 1 wherein a plurality of cohtinuous multifilament yarns are compacted to form the filament yarn into a flexible pack in which the yarn is textured in a random fashion; and

cutting the textured yarn after compacting into the pack to form a plurality of crimped staple fibers of various lengths.

10. A method according to claim 9, wherein the pack is cut completely therethrough during the cutting step to obtain crimped staple fibers of a variable length having a length distribution similar to that of wool.

11. A method according to claim 9, wherein the pack is not cut completely therethrough during the cutting step to obtain a partially cut pack of multifilaments of various lengths.

12. The method of claim 11, including the-step of twisting the multifilaments of various lengths of the partially cut pack to make a spun-like yarn.

13. A method for cutting at least one synthetic continuous multifilament yarn compacted into a l llexible pack in which the yarn is textured in a random fashion, wherein the pack is cut partially therethrough during the cutting step to obtain a partially cut pack having multifilaments of various lengths.

14. A method according to claim 13, including the step of twisting the multifilaments of various lengths of the partially cut pack to make a spun-like yarn. 

1. A method of cutting continuous multifilament yarns comprising the steps of: compacting at least one strand of multifilament yarn into a flexible piling in which the strand is curled in a random fashion, and cutting the strand after the strand has been compacted into the piling to form a plurality of separate strands of different lengths for use in further processing.
 2. The method of claim 1 wherein the strand is compacted by injecting the strand into an elongated tube with an expanding fluid.
 3. The method according to claim 1 wherein the piling is cut completely therethrough during the cutting step to obtain staple fibers of a variable length having a length distribution similar to that of wool.
 4. The method according to claim 1 wherein the piling is not cut completely therethrough during the cutting step to obtain a partially cut piling having individual strands of various lenghts.
 5. The method of claim 4 further including the steps of twisting the individual Strands of the partially cut piling to make thread.
 6. The method of claim 1 wherein a plurality of continuous multifilament yarns are compacted to form the flexible piling.
 7. The method of claim 1 wherein the multifilament yarns are made of synthetic materials.
 8. The method of claim 1 wherein the cutting step is performed continuously as the strand is compacted into the piling.
 9. A method for cutting synthetic continuous multifilament yarns comprising the steps of: compacting at least one synthetic continuous multifilament yarn into a flexible pack in which the yarn is textured in a random fashion; and cutting the textured yarn after compacting into the pack to form a plurality of crimped staple fibers of various lengths.
 10. A method according to claim 9, wherein the pack is cut completely therethrough during the cutting step to obtain crimped staple fibers of a variable length having a length distribution similar to that of wool.
 11. A method according to claim 9, wherein the pack is not cut completely therethrough during the cutting step to obtain a partially cut pack of multifilaments of various lengths.
 12. The method of claim 11, including the step of twisting the multifilaments of various lengths of the partially cut pack to make a spun-like yarn.
 13. A method for cutting at least one synthetic continuous multifilament yarn compacted into a flexible pack in which the yarn is textured in a random fashion, wherein the pack is cut partially therethrough during the cutting step to obtain a partially cut pack having multifilaments of various lengths.
 14. A method according to claim 13, including the step of twisting the multifilaments of various lengths of the partially cut pack to make a spun-like yarn. 